Benjamin foestnee



(No Model.)

PORSTNER.

, AUGER. No. 336,709. Patented Feb. 23, 1886.

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6L S/ H1!" WITNESSES: r 'INVENTOR BY Jam/m ATTORNEYS.

UNITED STATES PATENT OFFICE.

BENJAMIN FORSTNER, OF SALEM, OREGON, ASSIGNOR-OF ONE-HALF TO JAMES WALTON, OFSAME PLACE.

AUGER.

SPECIFICATION forming part of Letters Patent No. 336.709, dated February 23, 1886.

(No model.)

Jo'all whom it mag concern:

Be it known that I, BnxJAM'IN Fonsrnnn, a citizen of the United States, residing at Salem, in the county of. Marion and State of Oregon, have invented an Improvement in Angers, of which the following is a specification.

My present invention is animprovcment on an auger for which Letters Patent of the United States No. 155,148, were granted to me September 22, 1874.

The object of myinveution is to increase the efficiency of the anger and to diminish the costof manufacture.

Figure 1 isaside elevation of my improved auger. Fig. 2'isa plan view. Fig. 3 is used. tional elevation. 4

Similar letters of reicrencc indicate corresponding parts in the different figures of the drawings.

In angers of this class heretofore in use the peripheral cutting-edge has been a complete circle, and the oppositely-arranged cuttinglips,which extend from the centerof the anger to the peripheral cutting-edge,have formed at their junction with the cutting-edge enlargements, which interfered with the free working of the auger, and the peripheral cuttingedge required considerable pressure to force itinto the wood being bored. To remedy these do fects I have formed the peripheral cuttingedge on the circumference of a slotted disk, the edge being formed in two purts,ca,which begin at one of the slots of the disk and tcrminate at the other slot. Adjoining the extremity of each curved cutting edge thus formed there is a cutting-lip, b,which extends toward the center of the auger, and the two cutting-lips bare inclined slightly to the radii of the disk, and are connected by a central cutting-point, c. The slots d, which separate the cutters,are inclined in opposite directions, and at an angle suitable for forming the cuting-lips b. The cutting-lips b are sunk below the face of the auger, thus producing at the ends of each peripheral cutting-section a cutting-cdge, c, which facilitates the entrance'of the peripheral cutter into the wood being bored.

The slots d permit of readily sharpening the cutting-lips b, and furnish a ready escape for the chips produced by the cutters.

\Vhen my improved bit is revolved under pressure in contact with wood, the cuttinge edges a a determine the size of the hole, and

cut the wood around the periphery of thehole with a drawing cut, so that the chips which are afterward separated from the woodbythe cutters I), being already separated at the periphery of the l1ole,will be removed without tearing or roughcning the inner surface of the wood.

In the manufacture of my improved auger the slots b are formed by milling, thus facilii tating the manufacture and lessening the ex-t pcnse which necessarily attended the manufacture of the bit made under my former patent.

a central cutting-point, c, joining the cuttinglips b, substantially as herein specified.

2. As an improved article of manufacture, an anger formed of a shank carrying a slotted disk having on the circumference thereof peripheral cutters a a, provided with cuttingedges 0, inclined cutters b,'formed along the sides of the slots of the disk, and the cuttingpoint 0, joining the cutters b, substantially as herein specified.

BENJAMIN FORSTNER.

\Vitnessesz SETH R. HAMMER. FRANK KELLOGG Having th us described my invention, what I 7 claim as new, and desire to secure by Letters 

